Black holes, planetary mysteries and hidden matter revealed by NASA’s
Chandra X-ray Observatory
A black hole gobbles up matter in our own Milky Way Galaxy. A hot
spot of X-rays pulsates from near Jupiter’s poles. An intergalactic web of
hot gas, hidden from view since the time galaxies formed, is finally
revealed.
These scenarios sound like science fiction — but to those familiar
with the latest developments in X-ray astronomy, they are just a few of the
real-life discoveries made by NASA’s Chandra X-ray Observatory during its
third year of operation.
“Within the last year, Chandra has revealed another series of
never-before-seen phenomena in our galaxy and beyond,” said Chandra project
scientist Dr. Martin Weisskopf of NASA’s Marshall Space Flight Center in
Huntsville, Ala.
“When you combine recent discoveries with the secrets revealed
during the observatory’s first two years in orbit, it’s amazing how much
Chandra has told us about the universe in a relatively short period of
time.”
One such discovery was an unprecedented view of a supermassive black
hole devouring material in the Milky Way Galaxy – a spectacle witnessed for
the first time when Chandra observed a rapid X-ray flare emitted from the
direction of the black hole residing at our galaxy’s center.
In just a few minutes, Sagittarius A, a source of radio emission
believed to be associated with the black hole, became 45 times brighter in
X-rays, before declining to pre-flare levels a few hours later, offering
astronomers a never-before-seen view of the energetic processes surrounding
this supermassive black hole.
“When we launched the Chandra Observatory, we attempted to explain
its amazing capabilities in Earthly terms, such as the fact it can ‘see’ so
well, it’s like someone reading the letters of a stop sign 12 miles away,”
said Chandra Program Manager Tony Lavoie of the Marshall Center.
“But now that the observatory has been in orbit for three years, we
have unearthly proof of the technological marvel Chandra really is. Not only
has it continued to operate smoothly and efficiently, it has provided the
highest quality X-ray images ever made. Now, we’re not talking about stop
signs, but rather black holes, star systems, galaxies and planets.”
One such discovery involved the planet Jupiter. Using the Chandra
Observatory, astronomers discovered a pulsating hot spot of X-rays in the
polar regions of the planet’s upper atmosphere and uncovered evidence the
X-ray source is not arising from the region of Jupiter where previously
believed.
By revealing that most of the X-rays come from a hot spot appearing
at a fixed location near Jupiter’s north magnetic pole, Chandra disproved
the previous model, which placed the emission at a lower latitude of the
planet’s atmosphere and had no knowledge the X-rays were pulsed.
“Sometimes new discoveries provide answers, and sometimes they pose
more questions,” said Weisskopf. “This is a good example, because by
pinpointing the location of Jupiter’s hot spot, Chandra ruled out the
existing explanation for the planet’s X-ray emission. Now we must search
for a new process that explains Jupiter’s X-rays. When we accomplish that,
we can assemble yet another piece to the cosmic puzzle.”
One such piece fell into place when the Chandra Observatory
discovered part of an intergalactic web of hot gas and dark matter that
contains most of the material in the universe. The hot gas, which appeared
to lie like a fog in channels carved by rivers of gravity, has been hidden
from view since the time galaxies formed.
These observations, together with ultraviolet observations, helped
shed new light on how the universe evolved. The hot gas detected by Chandra
can be used to trace the presence of the more massive dark matter component.
The discovery of the hot gas may eventually enable astronomers to map the
distribution of dark matter in the universe and perhaps understand its
origin.
These recent discoveries build on a series of groundbreaking
findings made by the Chandra Observatory during its first two years of
operation. Initial highlights include its discovery of an X-ray ring around
the Crab Nebula, finding the most distant X-ray cluster of galaxies,
capturing the deepest X-ray images ever recorded and discovering a new size
of black hole.
Because Earth’s atmosphere blocks X-rays from reaching the surface,
X-ray astronomy can only be performed from space. Launched in July 1999,
the Chandra Observatory travels one-third of the way to the Moon during its
orbit around the Earth every 64 hours. At its highest point, Chandra’s
highly elliptical, or egg-shaped, orbit is 200 times higher than that of its
visible-light-gathering sister, the Hubble Space Telescope.
The Marshall Center manages the Chandra program, and TRW, Inc. of
Redondo Beach, Calif., is the prime contractor for the spacecraft. The
Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls
science and flight operations from Cambridge, Mass.
Images associated with this release are available at:
